Working ten hour days allows you to fall behind twice as fast as you could working five hour days.

The greatest weapons in the conquest of knowledge are an understanding mind and the inexorable curiosity that drives it on.

All normal life, Peter, consciously or otherwise, resent domination. If the domination is by an inferior, or by a supposed inferior, the resentment becomes stronger.

I never considered myself a patriot. I like to think I recognize only humanity as my nation.

Unfortunately, in many cases, people who write science fiction violate the laws of nature, not because they want to make a point, but because they don't know what the laws of nature are.

Suppose that we are wise enough to learn and know - and yet not wise enough to control our learning and knowledge, so that we use it to destroy ourselves? Even if that is so, knowledge remains better than ignorance. It is better to know - even if the knowledge endures only for the moment that comes before destruction - than to gain eternal life at the price of a dull and swinish lack of comprehension of a universe that swirls unseen before us in all its wonder. That was the choice of Achilles, and it is mine, too.

I even got a letter from a young woman in British Columbia that began as follows: 'Today I am eighteen. I am sitting at the window, looking out at the rain, and thinking how much I love you.'